The present invention relates generally to operations performed, and equipment utilized, in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides an expandable well screen.
It is useful in some circumstances to be able to convey generally tubular equipment into a subterranean well, position the equipment within a wellbore of the well, and then outwardly expand the equipment in the wellbore. For example, a restriction in the wellbore may prevent the equipment in its expanded. configuration from passing through that part of the wellbore, but the equipment may pass through the restriction in its retracted configuration. In one application of this principle, it is known to use expandable well screens in wellbores.
An example of the potential usefulness of expandable equipment in a wellbore is where the wellbore intersects a productive, relatively unconsolidated, formation. It would be desirable in many situations to be able to utilize a well screen to filter production from the formation, while foregoing the expense of cementing casing in the wellbore and performing a gravel packing operation. Unfortunately, without any radial support the unconsolidated formation would likely collapse into the wellbore, causing additional expense and loss of revenue. Conventional nonexpandable well screens must necessarily be smaller than the wellbore in order to be conveyed therethrough, and so they are incapable of providing any radial support for an unconsolidated formation. Conventional expandable well screens are not designed for contacting and providing radial support for a formation, and so are unsuited for this purpose.
Therefore, it can be seen that it would be quite desirable to provide an expandable well screen which may be used for contacting and providing radial support for a formation intersected by a wellbore. It would also be desirable to provide an expandable well screen having enhanced torsional and tensile strength. It is accordingly an object of the present invention to provide such an expandable well screen.